(i) Technical Field
The present invention relates to focal plane shutters and optical apparatus.
(ii) Related Art
Japanese Unexamined Patent Application Publication No. 2002-296640 discloses a focal plane shutter in which a shutter opens and closes an opening of a board.
The shutter includes plural blades. The shutter moves and closes the opening such that an overlapped state where the plural blades overlap each other is shifted to an expanded state where the plural blades expand. Herein, an overlapping amount of the plural blades is reduced in the expanded state, so that the shutter might be warped. For this reason, when the shutter moves from the overlapped state to the expanded state, the shutter might be warped to come into contact with the board. As a result, the shutter might be damaged.